Dr. Marc Mauer, president of the National Federation of the Blind, at podium, speaks at a ceremony where senior NASA officials presented the NFB with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

Dr. Marc Mauer, president of the National Federation of the Blind speaks at a ceremony where senior NASA officials presented the NFB with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

NASA astronaut Greg Johnson, left, speaks with Dr. Marc Mauer, president of the National Federation of the Blind, right, prior to a ceremony where senior NASA officials presented the NFB with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

Dr. Marc Mauer, president of the National Federation of the Blind accepts an award from William Gerstenmaier, Associate Administrator, Space Operations, NASA Headquarters at a ceremony where senior NASA officials presented the NFB with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

Dr. Marc Mauer, president of the National Federation of the Blind, left, accepts two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009 from NASA Associate Administrator Chris Scolese, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)